Costumes by Edith Head, and an uncredited Hubert de Givenchy
There are few moments in film as unsurprising but still breathtaking as Audrey Hepburn returning from Paris a new woman, in French couture, no less, in Sabrina. It's Audrey fucking Hepburn, she's gorgeous no matter what, and her frumpy girl next door--rather, girl above the garage--look is completely unbelievable. Just look at that bone structure. But once her transformation is complete, as the viewer one can't help but be struck by her fragile, ethereal beauty and Givenchy's masterful gowns. No wonder that grand dame of Tinseltown tailoring, Edith Head took all the credit. And the Oscar.